Patent Application
20140131015
The present invention relates to cooling systems for battery packs and, in particular, to battery packs using turbulent air flow cooling systems.
Large capacity rechargeable batteries are currently being investigated for use in electric vehicles. The ultimate feasibility of electric vehicles depends on significantly reducing the associated costs. Reduction in the costs of battery assemblies is particularly important.
Lithium ion batteries are an important type of battery technology. Most battery assemblies, including lithium ion battery assemblies, include a plurality of individual electrochemical cells. Typically, such electrochemical cells include an anode and a cathode. Typically, the anode includes a metal sheet or foil (usually copper metal) over-coated with a graphitic layer. Similarly, the cathode usually includes a metal sheet or foil (usually aluminum metal) over-coated with a lithium-containing layer. Finally, electrochemical cells include an electrolyte which is interposed between the anode and the cathode. Terminals allow the generated electricity to be used in an external circuit. Electrochemical cells produce electricity via an electrochemical reaction.
For high power application, a plurality of battery cells are utilized and assembled into a battery module. Moreover, such battery modules are assembled into battery packs which include a cooling system and related electronics for operating the batteries. The cooling systems typically include a plurality of metallic (e.g., copper and/or aluminum) cooling fins interspersed between the battery cells. It turns out that the assembly of such battery modules is fairly difficult with respect to aligning the cooling fins and the battery cells. Moreover, other prior art cooling systems utilize air coolant that impact a plurality of dimples to increase air flow speed.
Accordingly, there is a need for improved battery pact cooling systems.
The present invention solves one or more problems of the prior art by providing in at least one embodiment, a cooling system for a battery pack. The cooling system includes a fluid source for providing cooling fluid and a turbulator in which the cooling fluid flows along an average flow direction. The turbulator includes a first support member, a second support member, a third support member, a first plurality of rods positioned between the first support member and the second support member, and a second plurality of rods positioned between the second and the third support members. The first plurality of rods is offset from the second plurality of rods in a direction perpendicular to the average flow direction. Finally, the first plurality of rods and the second plurality of rods disrupt air flow from the fluid source into non-laminar flow. Advantageously, the cooling system and turbulator of the present embodiment, increase air speed and promote the uniform heat balance between the opposite walls in the channel of the turbulator in which cooling fluid flows.
In another embodiment, a battery pack integrating the cooling system set forth above is provided. The battery pack includes a plurality of battery cells and a plurality of turbulators disposed between adjacent battery cells in the plurality of battery cells in which cooling fluid flows along an average flow direction. Each turbulator includes a first support member, a second support member, a third support member, a first plurality of rods positioned between the first support member and the second support member, and a second plurality of rods positioned between the second and the third support members. The first plurality of rods is offset from the second plurality of rods in a direction perpendicular to the average flow direction. Finally, the first plurality of rods and the second plurality of rods disrupt fluid flow from the fluid source into non-laminar flow.
Exemplary embodiments of the present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
Reference will now be made in detail to presently preferred compositions, embodiments and methods of the present invention, which constitute the best modes of practicing the invention presently known to the inventors. The Figures are not necessarily to scale. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for any aspect of the invention and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.
Except in the examples, or where otherwise expressly indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and/or use are to be understood as modified by the word “about” in describing the broadest scope of the invention. Practice within the numerical limits stated is generally preferred. Also, unless expressly stated to the contrary: the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures of any two or more of the members of the group or class are equally suitable or preferred; the first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation; and, unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property.
It is also to be understood that this invention is not limited to the specific embodiments and methods described below, as specific components and/or conditions may, of course, vary. Furthermore, the terminology used herein is used only for the purpose of describing particular embodiments of the present invention and is not intended to be limiting in any way.
It must also be noted that, as used in the specification and the appended claims, the singular form “a,” “an,” and “the” comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.
Throughout this application, where publications are referenced, the disclosures of these publications in their entireties are hereby incorporated by reference into this application to more fully describe the state of the art to which this invention pertains.
The term “turbulator” refers to a device that turns laminar flow into non-laminar flow, and in particular, into turbulent flow.
The term “laminar flow” refers to fluid flow (e.g., air flow) occurring in parallel layers without disruption between the layers. Alternatively, “laminar flow” as used herein refers to flow with a Reynolds number less than 1000.
The term “non-laminar flow” refers to fluid flow that is not laminar. Alternatively, “non-laminar flow” as used herein refers to flow with a Reynolds greater than 1000.
The term “turbulant flow” refers to fluid flow with a Reynolds greater than 2000. Alternatively, “turbulant flow” as used herein refers to flow with a Reynolds greater than 3000.
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While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.
